Sample changer for radio-active samples using endless flexible means for sample transportation



H. SCHOLZ ETAL Jan. 31, 31967 SAMPLE CHANGER FOR RADIO-ACTIVE SAMPLESUSING EN FLEXIBLE MEANS FOR SAMPLE TRANSPORTATION Original Filed Aug.18, 1959 5 Sheets-Sheet 1 INVENTORS PE WM? IC Mmem F SGHOLZ H. SCHOLZETAL Jan. 31, 1967 SAMPLE CHANGER FOR RADlOACTIVE SAMPLES USING ENDLESSFLEXIBLE MEANS FOR SAMPLE TRANSPORTATION 5 Sheets-Sheet z Original FiledAug. 18, 1959 NVENTORS PETAR PALIO HERBERT SGHOLZ AGENT 167 H. SCHOLZETAL 3302M SAMPLE CHANGER FOR RADIO'ACTIVE SAMPLES USING ENDLESSFLEXIBLE MEANS FOR SAMPLE TRANSPORTATION Original Filed Aug. 18, 1959 5Sheets-Sheei 3 AGENT United States Patent Office 3,3d2fi25 Patented Jan.31, 1967 8 Claims. cl. 250-106) The present application is acontinuation of US. patent application Serial No. 834,601 filed August18, 1959, and now abandoned.

This invention relates to Changers of samples for investigations in thearea of radio-activity, the preparations tobe tested being ledsuccessively along a radiation meter and each time remaining under thesame for anadjustable period of time.

Sample changers are 'known in which a table with the cups for containingthe samples grouped on its periphery can be turned in steps so that apreparation under investigation can be combined with a radiation meterfor a certain period which is pre-determined. If desired, the timeduring which the sample remains under the radiation meter may also bededuced from counts. The necessary controls and mechanical manipulationsare comparatively complicated, since it is always necessary to ensurethat the preparation being tested is substantially shielded with respectto the surroundings and is not influenced by adjacent preparations.Consequently, in addition to the transportation movements furthermovements of the preparation cups into the shielding chamber arenecessary.

The novel sample changer, which is characterized by a driven endlesschain or system of chains as a transprtation means and accommodation forreceiving the prepara tion cups and lifting them in steps from the chainand the supply of the cups into the shielding chamber containing theradiation meter, may be much simpler of construction and much easier tohandle in operation, since the chain and the preparation cups can movebetween stationary parts of the device. Furthermore, more preparationsthan in conventional sample changers can be housed in the same space andon the same surface.

In order that the invention may be readily carried into effect, severalembodiments will now be described, in detail, by Way of example, withreference to the accompany ing drawings, in which:

FIG. 1 shows a chain guide for the samples;

FIG. 2 is a diagrammatic view with a shielding chamber and,

FIG. 3 shows the driving device for the embodiments of FIG. 1.

FIGS. 4 and 5 are a plan and sectional view respectively of analternative embodiment of the present invention and FIGS. 6 and 7 are aplan and sectional view respectively of another alternative embodimentthereof.

Referring now to FIG. 1, an endless articulate chain or flexible belt,which may alternatively be of synthetic material, comes between junctionrods 6 of chain 1 by meshing of the teeth 2 of double gear wheels 3, 4,5 and 3', 4', 5 respectively. The gear wheel 4, which is driven by anelectric motor 7 as a function of the count, meshes via the teeth 8, 9and 8, 10 respectively, without play with the gear wheels 3 and 5, whilechain 1 is laid on the teeth 2 of the gear wheels 3, 4, 5. Guide wheels11 and 12, which rotate freely, are fitted, preferably with a slightpossibility of displacement for the shafts in slot guides 13 and 14 toenable any play occurring in the chain to be eliminated.

The chain 1 is led through a front chamber 15 of a shielding chamber 16,preferably of lead, as may be seen from FIG. 2. The preparation cups 17may be secured to chain 1 either by clamping or in other suitablemanner.

After the preparation cup 17 has arrived in front chamber 15 and thefeed movement of chain 1 has ceased, an electric motor sets in knownmanner a rectilinearly-guided supply member 18 into movement whichembraces the cup in a bifurcated manner, lifts it from the chain andslides it into shielding chamber 16. The cups may be i positioned as aclose fit in small depressions of the chain,

from which they are pushed out by the supply member 18 and an oppositemember 19 during their movement into shielding chamber 16. The cup isreplaced onto the chain ing motor 7 each cup arrives exactly in frontchamber 15.

Step-switching relays or gontinuous drives may be used as controlleddriving motors, the latter being provided with ratchet devices in orderto ensure the superposition of each cup individually. p

The invention is not limited to the embodiment shown. It isalternatively possible, for example, for two chains to be introducedside by side, in steps, into separate front chambers for separateshielding chambers containing separate radiation meters. in this case,the guide for the chain drive must of course, be such that themeasurements do not overlap.

The bifurcated supply member 18 has small springs 18' which can bear inapertures 19 of the opposite member 19 so that the opposite member,which serves for the proper transportation of the cups, is; taken alongto stops 16 in the guide of shielding chamber 16. The supply memberreturns to its stop whereas the cup remains on the chain, which isensured by corresponding projections 1' on the chain. Next, the chainmoves on one step and a new cup is introduced into shielding chamber 16.

A chain may alternatively be shortened or lengthened by removing oradding chain links. It is also possible for portion of the chain,including the preparation cups, to be led into a longer shieldingchannel on each side of front chamber 15, which is likewise shielded.

As a further alternative, the chain guide may be chosen differently bythe addition of further driving wheels or guide wheels, it beingessential only that the endless chain should be introduced into thefront chamber substantially in a straight line.

For very sensitive measurements it is readily possible to provide a lockwhich is coupled to the drive for the chain, so that a cup present inthe front chamber is already wholly shielded from the surroundings. Inthis embodiment, the radiation meter may sometimes be arranged in thefront chamber and the feed movement provided in a separate shieldedchamber. The lock surfaces located on the side above the chain are notfilled until the cup is moved on, to be closed again as soon as a newcup is in the proper position under the radiation meter.

It is also possible to control the supply member by means of the sameelectric motor which drives the chain, it a correspondingly controlledcoupling is provided.

In this embodiment, it would be possible to dispense with a separatemotor for supplying the cup into the shielding chamber proper containingthe radiation meter.

For the transportation of the sample cups, it is alternatively possibleto use two chain paths 21 and 22 of two chains 23 and 24, which arelocated side by side or one above the other, as shown diagrammaticallyin FIGS. 4 and 5. In this case, a guide member 27 guided in a guidegutter 26 is associated with each sample cup and, in the case of chainslocated one above the other, for example, a hook-like member (FIG. whichmay be clamped on the end surfaces 21 and 22 and which is driven by thetwo parallel-guided chain paths as long as the chain paths 21, 22 and21', 22 of guide gutter 26 are parallel. The cup may then be enclosedeither in the course of the parallel-guided chain paths or at the end inshielded chambers containing the radiation meters, end 28 of theparallel guide. After measurement, the guide member 27 may again bepicked up at 28, by two further chain paths 2% and 29' or by there-joined chain paths 21", 22".

In another embodiment as shown in FIGS. 6 and 7, chains 30 and 31 havingball joints 3G, 31' are located side by side with a guide member 32having a cup 25 which is clamped for example, between the end walls 33,33 of the chains. The guide member 32 slides into a guide gutter 34 andthe chains driven by rollers 35, 35 serve to move on the cups. Due tothe ball joints in the chains, guiding of the chains along slightlycurved paths is also readly possible so that again juxtaposed closedchain paths may be obtained, the rollers 35, 35 in corn tradistinctionto the embodiment of FIG. 4 being journalled in the plane of thedrawing. At the area where the guide member 32 with its cup must beintroduced into the shielded measuring chamber, the chains 30 and 31slightly move apart as the guide member 32 moves through the measuringchamber. After having been moved out of the measuring chamber, the guidemember 32 is brought onto the chains 30 and 31, which then againoperates closely side by side and provides for the furthertransportation of the cups.

What we claim:

1. A sample changer for radioactive samples employed with a detectorcomprising a plurality of sample holders, a shielding chamber containingsaid detector, an endless flexible belt for transporting said samples tobe tested suc cessively adjacent the operating area of said detector,means for driving said endless flexible belt, and means for engagingsaid sample holders and moving the same from said endless flexible beltto deposit each sample holder into said shielding chamber containingsaid detector.

2. A sample changer for radioactive samples employed with a radiationmeter comprising a plurality of sample holders, a shielding chambercontaining said radiation meter, a chain system for transporting saidsamples to be tested successively within the operating range of saidradiation meter, means for driving said chain system, and means forengaging said sample holders and lifting the same from said chain systemto deposit each sample holder into said shielding chamber containingsaid radiation meter.

3. A sample changer for radioactive samples employed with a radiationmeter comprising a plurality of sample holders, a shielding chambercontaining said radiation meter, an endless chain system fortransporting said samples to be tested successively Within the operatingrange of said radiation meter, means for driving said chain systemincluding a plurality of gear wheels with interengaging teeth, and abifurcated member for engaging and lifting said sample holders from saidchain and transporting them into said shielding chamber and returningsaid sample holders on said chain after measurement by said radiationmeter.

4. A sample changer for radioactive samples employed with a radiationmeter comprising a plurality of sample holders, a shielding chambercontaining said radiation meter, a chain system for transporting saidsamples to be tested successively within the operating range of saidradiation meter, a double gear Wheel drive having interengaging guidewheels, said double gear wheel drive meshing with the chain links ofsaid chain system and said guide wheels for driving said chain system,and means for engaging said sample holders and lifting the same fromsaid chain system to deposit each sample holder into said shieldingchamber containing said radiation meter.

5. A sample changer for radioactive samples employed with a radiationmeter as claimed in claim 2 wherein said chain system includes at leasttwo separate chains, each having separate sample holders thereon.

6. A sample changer for radioactive samples employed with a radiationmeter as claimed in claim 5 wherein said two separate chains are locatedside-by-side.

7. A sample changer for radioactive samples employed with a radiationmeter comprising a plurality of sample holders, a shielding chambercontaining said radiation meter, a chain system having spaceddepressions therein for holding and transporting said sample holders,said chain system having guide tracks and guide members movable thercin,said samples being tested successively Within the operating range ofsaid radiationmeter, a double gear wheel means for driving said chainsystem, and means for engaging said sample holders and lifting the samefrom the spaced depressions in said chain system to deposit each sampleholder into said shielding chamber containing said radiation meter.

8. A sample changer for radioactive samples employed with a radiationmeter as claimed in claim 2 wherein said chains are provided with balljoints.

References Cited by the Examiner UNITED STATES PATENTS 3/1950 Henriques2501 06 X OTHER REFERENCES RALPH G. NILSON, Primary Examiner.

ARCHIE R. BORCHELT, Examiner.

2. A SAMPLE CHANGER FOR RADIOACTIVE SAMPLES EMPLOYED WITH A RADIATIONMETER COMPRISING A PLURALITY OF SAMPLE HOLDERS, A SHIELDING CHAMBERCONTAINING SAID RADIATION METER, A CHAIN SYSTEM FOR TRANSPORTING SAIDSAMPLES TO BE TESTED SUCCESSIVELY WITHIN THE OPERATING RANGE OF SAIDRADIATION METER, MEANS FOR DRIVING SAID CHAIN SYSTEM, AND MEANS FORENGAGING SAID SAMPLE HOLDERS AND LIFTING THE SAME FROM SAID CHAIN SYSTEMTO DEPOSIT EACH SAMPLE HOLDER INTO SAID SHIELDING CHAMBER CONTAININGSAID RADIATION METER.